In recent television receivers (referred as TV receivers), digital controls for a reception channel selection and a sound volume control are very popular.
Such a TV receiver has a keyboard for manual controls of the TV receiver, a microcomputer for performing digital controls of the TV receiver, a memory storing a variety of control data and a tuner. The keyboard is mounted on a front panel or a remote controller of the TV receiver. The microcomputer reads out a suitable operation data, e.g., a tuning voltage data from the memory in response to an operation of the keyboard. The memory is generally comprised of a read only memory (referred as ROM hereafter).
The operation data, e.g., the tuning voltage data read out from the ROM are converted to an analog tuning voltage by a conventional digital to analog converter (referred as D/A converter hereafter) and the analog tuning voltage is applied to the tuner. The tuner is generally comprised of a voltage synthesizer tuning circuit. The tuning voltage is applied to a variable capacitance diode in a resonant circuit of the tuner. Thus, the tuner performs a prescribed tuning for a desired TV reception channel designated by the keyboard.
In such a conventional TV receiver, there has been developed a reception control apparatus which is equipped with another memory. The second memory is comprised of a random access memory (referred as RAM hereafter) which temporarily stores an operation data read out from the ROM upon operation of the keyboard or at predetermined time intervals during the operation of the TV receiver.
The operation data stored in the RAM are held even after a power shut-off of the TV receiver. For the purpose, the RAM is always activated by a suitable auxiliary power supply source like a battery. Thus, a prescribed channel reception at the last power shut-off can be automatically restored at the power turn-on operation of the TV receiver.
An example of the conventional reception control apparatus for the TV receiver is shown in FIG. 1. FIG. 1 is a block diagram illustrating the conventional reception control apparatus. In FIG. 1, a keyboard 11 is coupled to a system controller 12. The keyboard 11 is conventionally equipped with a power controller, a channel controller and a volume controller, but they are not shown in the drawing. The power controller controls the turn-on or the shut-off of a main power supply source of the TV receiver. The channel controller controls the selection of the TV reception channels. The volume controller controls the loudness of sound from the TV receiver.
There are at least two types for the channel controller. One type of the channel controller has a prescribed number of channel keys associated to the TV reception channels, i.e., Ch-1, Ch-2, . . . , Ch-12, Ch-U, respectively. Another type of the channel controller has two keys, one for raising the count of the channel numbers and another for lowering the count of the channel numbers. The volume controller has two keys for increasing and decreasing sound volume.
When any key on the keyboard 11 is operated by a user, the keyboard 11 outputs a reception control data D1 associated to the operated key.
The system controller 12 is constituted by a microcomputer. Necessary operations of the system controller 12 are performed, for example, by suitable software programmed in the microcomputer for operations as described later.
When a specified key on the keyboard 11 is operated, the system controller 12 reads out a specified operation data D2 from and ROM 13 coupled thereto, in response to the reception control data D1 associated to the operated key on the keyboard 11. The ROM 13 stores a plurality of the operation data D2. The plurality of the operation data D2 includes different voltage data, e.g., tuning voltage data D2-ch and volume voltage data D2-s. The tuning voltage data D2-ch, e.g., D2-1, D2-2, D2-3, . . . , D2-12, D2-U correspond to the TV reception channels Ch-1, Ch-2, . . . , Ch-12, Ch-U, respectively.
The tuning voltage data D2-ch and the volume voltage data D2-s read out from the ROM 13 are applied to a tuning circuit 14 and a volume control circuit 15 of a tuner 16 through a D/A converter, respectively. The D/A converter is not shown in the drawing, but is comprised in the system controller 12 as a part of the microcomputer. The D/A converter converts the digital tuning voltage data D2-ch or the volume control voltage data D2-s to a corresponding analog tuning voltage D3, e.g., an analog tuning voltage D3-ch or an analog volume control voltage D3-s.
The tuning voltage D3-ch is applied to a variable impedance device such as a variable capacitance diode comprising a resonant circuit of the tuning circuit 14. Thus, a desired TV reception channel is tuned by the tuning circuit 14 in response to the reception control data D1 designated to a specified channel key on the keyboard 11.
The volume control voltage D3-s is applied to a volume control circuit 15. Thus, a desired loudness is obtained in response to the reception control data D1 associated by the volume controller on the keyboard 11.
The system controller 12 is further coupled to an RAM 17 for temporarily storing the operation data D2 such the the tuning voltage data D2-ch and the volume control voltage data D2-s. The operation data D2 is applied to the RAM 17 at a prescribed time, as described later.
Referring now to FIG. 2, a reception channel selection routine of the system controller 12 in the course of the operation of the TV receiver. FIG. 2 is a flowchart showing the selection routine. The user of the TV receiver operates the channel controller of the keyboard 11 so that a prescribed reception control data D1 corresponding to his or her desired TV channel is applied to the system controller 12 (Step 2A).
The system controller 12 reads out a specified tuning voltage data D2-ch from the ROM 13 in response to the reception control data D1 applied from the keyboard 11 (Step 2B). The D/A converter comprised in the system controller 12 converts the tuning voltage data D2-ch of digital configuration to a corresponding tuning voltage D3-ch of analog configuration and then applies the tuning voltage D3-ch to the tuning circuit 14 of the tuner 16 (Step 2C). Thus, the desired TV channel program is received by the TV receiver.
The system controller 12 further applies the tuning voltage data D2-ch to the RAM 17 when the channel controller of the keyboard 11 is operated (Step 2D). The tuning voltage data D2-ch is temporarily stored in the RAM 17 (Step 2E). But, the tuning voltage data D2-ch, e.g., D2-3, stored in the RAM 17 is replaced by another tuning voltage data D2-ch, e.g., D2-5, when another operation for the channel controller of the keyboard 11 is made.
The RAM 17 is always activated by an auxiliary power supply source (not shown). Thus, the tuning voltage data D2-ch stored in the RAM 17 is held even after a main power supply source for the TV receiver is shut-off by the operation of the power controller on the keyboard 11.
Referring now to FIG. 3, an operation routine of the system controller 12 at the power turn-on operation of the TV receiver. FIG. 3 is a flowchart showing the operation routine. For the power turn-on of the TV receiver, the power controller on the keyboard 11 is operated by the user (Step 3A). Thus, a prescribed reception control data D1 is applied to the system controller 12. The system controller 12 automatically accesses the RAM 17 upon receipt of the reception control data D1 (Step 3B). Then, the system controller 12 reads out a tuning voltage data D2-ch from the RAM 117, which has been held at the last power shut-off operation of the TV receiver.
The D/A converter in the system controller 12 converts the tuning voltage data D2-ch of the digital configuration to a tuning voltage D3-ch of analog configuration and then applies the tuning voltage D3-ch to the tuning circuit 14 of the tuner 16 (Step 3C). Thus, a program at the TV channel received just before the last power shut-off operation is received by the TV receiver.
However, the conventional channel selection apparatus has a drawback as follows.
Generally, users have their own habit on the TV channel receptions through a day or a week. In their reception patterns due to the habit, desired reception channels are used to be different with each other, time by time in a day or a week. Therefore, a user wish to receive different TV channels for different times in a day or a week.
The conventional channel selection apparatus for a TV receiver is unable to satisfy such a demand according to the user's habit or the reception pattern in a day or a week.